Sheep shears



Oct. 6, 1931. F. w. sco'rT 1,825,890

. SHEEP SHEARS Fil'ed Aug.- 7. 1929 Patented Oct. 6 1931 UNITED STATES FRANK W. SCOTT, OF KIRKLAND, ILLINOIS SHEEP SHEAR-S Application filed August 7, 1929.

of the cutter and comb may necessitate increased tension. Sheep shears are therefore commonly provided with a tension adjustment adapted for quick and easy manipulation by theoperator. The most common obj ections to the tension adjustments now provided have been that they are all apt to be affected by the vibration incident to the operation-of the tool, and that they are .apt

- to be changed by having the adjustable part turned by rubbing against something in the operation of the tool. The operator, in other words, could never be sure after adjusting the tool for the proper tension, that the tool would keep that adjustment. Evident-1y it was never conceived to be practical to provide a lockor catchfor the adj ustmentv; mere friction was relied upon to hold the adjustable part in adjusted position. It is one of the principal objects of my inventionto provide an improved tension adjustment incorporating a positive lock by means of which the tool, once its tension has been adjusted, can be definitely insured of retaining such adjustment until it is desired to change the 1' same.

According to my invention the vibrator member which carries the tension member is equipped with an adjusting screw, the turn- .ing of which in one direction or the other increases or decreases the tension, and a thumb nut is provided in connection with said screw normally held under spring pressure in interlocked relation with the vibrator member so as to oscillate with it and the screw in the normal operation of the tool.-

The thumb nut is arranged, however, to be pulled out of interlocked relation with the vibrator against the action ofthe spring and is then arrangedin the turning thereof to turn the screw in the one direction or the other Serial No. 384,164.

depending on the tension adjustment desired. After such an adjustment has been made the thumb nut is released and moved under spring action back to interlocked relation with the vibrator. Thus, while the tension adjustment can be manipulated easily and quickly to increase or decrease the tension as and when desired, the operator can always feel that when he has adjusted the tension the tool will keep that adjustment until he changes it. A special feature preferably incorporated in the tension adjustment is the provision of a slip-sleeve arranged to serve as an intermediate wear member fitting on the lower post of the vibrator and locked thereto so as to oscillate therewith in the bearing. The tension adjustment is inside this sleeve and is, therefore, unaffected by wear, and can always be operated easily. The sleeve is preferably also arranged to be locked to the post of the vibrator in different positions so that when one side thereof is worn, the sleeve can be turned to bring an unWorn portion thereof into position. i

Another serious ditficulty with sheep shears has been that of keeping the cutter attached a to its fork even when there is not the proper amount of tension. It has been the practice to provide cone points .on the fork fitting in plain round holes in. the cutter. The cones soon had grooves worn therein and thereafter could not take their own seat in the holes and, furthermore, would slip out of the holes very easily, especially if the tension happened to be a bit-too light. It is, therefore, still another important object of my' invention to improve the-connection between the fork and the cutter so that the fork has a positive hold even under light tension and there is not the slightest possibility of the cutter coming olf. Briefly stated, I provide points on the fork rounded on the ends to'fit in similarly counterbored holes in the cutter so that line contact between the points on the fork and the cutter is avoided and surface contact substituted, the points beingself-adjusting or self-seating in the holes, and further provide projecting nibs .on said pointsarranged to project freely through the holes in the cutter sufliciently to maintain the connection between the fork and the cutter even though the tension may be too light, the said nibs fitting in the holes freely enough to allow the points of the fork enough movement relative to the cutter to take their own seat.

The invention is illustrated in the accompanying drawings, wherein Figure 1 is a plan view of a tool of the kind referred to embodying my invention;

Fig. 2 is a central vertical longitudinal section taken on the line 2r2 of Fig. 1, showing the tension adjustment in elevation;

Fig. 3 is a central vertical section through the tension adjustment showing the same on an enlarged scale, and

Fig. 4 is a section on an enlarged scale taken on the line H of Fig. 1.

The same reference numerals are applied to corresponding parts throughout the views.

The sheep shear illustrated is made in accordance with my Patent 1,692,870, issued November 27 1928, and comprises a frame 5 providing a handle portion 6 by which the tool is grasped for use. The handle 6 is hollow and provides a bearing for the terminal driving element 7, driven in the usual manner by connection with a flexible drive shaft at the outer end of the handle, as is well known in this art. The element 7 terminates within the housing 8 in a crank portion 9 having a ball 10 swiveled on the crank end thereof and arranged for operation in a ball race provided in the cross head 11, whereby it produces vibratory movement of the actuator for the cut- 86 ter 12 and reciprocates the same relative to the comb 13. As described in my patent, the cutter actuator, designated generally by the reference numeral 14, comprises a vibrator member 15 and a tension member 16. The

member 15 has the cross head 11 formed preferably integral with the rearward end thereof and extends forwardly toward the cutter 12, the forward end being conformed to provide a yoke 17 having a bearing opening 18 therein for the reception of the intermediate por- -tion of the tension member 16. The vibrator member 15 has axially aligned trunnions 19 and 20, the former of which is provided by the threading of a plug in the top of the vibrator 15, as shown at 21. The other trunnion is suitably formed integral with the vibrator. The plug 19 has a rounded end fitting in a bearing 22 provided in a plug 23 threaded in a hole 24 in the top wall of the housing 8. Facets are provided on the plug 19 for the application of a socket wrench cntered through the hole 24 for threading or unthreading the same. A bushing 25 threaded in another opening 26 in the lower 00 wall of said housing provides a bearing for the trunnion 20. Further reference will be made hereinafter to various important features of the bearing of the trunnion 20 in the bushing 25. Ample bearing is provided for 06 the vibrator member and Vibration and its accompanying wear is accordingly reduced to a minimum. The end thrust of the plug 19 resulting from the tension placed upon the cutter 12, as will presently appear, is assumed by the bearing 22. The latter is both a journal and an end thrust bearing for the plug 19 and is preferred to other more complicated constructions from the standpoints of simplicity and economy.

The tension member 16 has a rocker mounting in the bearing opening 18, previously referred to, so as to have capacity for cndwise and lateral rocking movement. The capacity for endwise rocking movement permits the application of pressure on the cutter 12 by the forward end of the tension member while the capacity for lateral rocking movement,aswill appear shortly, permits the tension member to accommodate the cutter 12 to the comb 13 throughout the length of its sweep. The tension member 16 for the latter reason is forked at its outer end and has the spread fingers 27 thereof provided with the points 28 for reception in holes 29 provided in the prongs of the cutter 12, which may have two, three or more prongs. The tension member thus engages the cutter at separated points in the are of its reciprocation and, by reason of its capacity for lateral rocking movement, accommodates the cutter to the comb throughout its sweep, which, of course, makes for smooth and easy operation of the too]. By reference to Fig. 4 it will be observed that the points 28 are rounded on the ends thereof and that the holes 29 are corres iondingly counterborcd to provide seats therefor in which the points have surface contact as distinguished from the line contact afforded otherwise where the points were conical and fitted in plain round holes in the cutter. The ball and socket connection thus atl'ordcd makes the points self-adjusting or self-seating in the holes under all tension adjustments, it being obvious that the lingers 27 can be swung slightly up or down with reference to the cutter, and that the points will seat in the same way in each position assumed by the fingers. This, if course, as impossible with the cone points, especially after they had become slightly grooved as a result of the line contact between the cone points and the plain round holes in the cutter. Furthermore, it will be noted that I have provided nibs 31 on the points 28 arranged to project through the holes 29 sufficiently to maintain a good connection between the fingers 27 and the cutter even though the rounded ends of the points 28 may be fitting rather loosely in the counterbored seats, the nibs 31 will not allow the cutter to come off in the event there is some slight disturbance in the sweep of the cutter over the comb caused, for example, by the riding of the cutter over gum on the comb. The importance of insuring a positive connection between the cutter and the fork cannot be over emphasized; if one finger of thefork becomes detached, there is clanger of the fork turning? so that the point thereof catches between the teeth of the eonib, which would mean either the shearing oft of the point, the damaging of the comb, or the possibility of breakage of some other part of the device because of the excessive resistance imposed on the operation of the vibrator; Such a condition is entirely obviated by the imp ovement just described The tension member 16 extends rearwardly from the cutter and inter-seets the tub cruni axis of the vibrator member, the rear end being extended through an opening 32 provided in the wall of the trunnion 20. An adjusting screw 33 threadin in the trunnion 20 has a ball end 34 engaging in a com lementary recess 35 provided in the underside of the rear end of the tension member 16. Manifestly, ti htening of the screw 44 forces the end of the tension member 16 upwardly and rocks the same relative to the bearing 18 as a fulcrum so th t the forked ,1 front end is forced downwardl and presses the cutter against the comb 13, the pressure on the cutter being" equalized by reason of the spread fing'rs 27 of the fork. A coiled compression spring 36 acting between the plug 19 and the top of the tension ineinber'lti at the rearend of the latter serves to hold the tension member in close; contact with the screw 33 so that any tendency to rattle or chatter is entirely eliminated and very close I and aeourate adjustment of the tension on the cutter may be made. The spring 36 also serves to raise the forked front end of the tension member when the screw 33 is loosened to releu'se the cutter 12 for replacement or sharpening thereof. A change in cutters can, therefore, be made with very little diiiiwhy and without loss of time. It Wlll be observed that I have inserted a flat headed rivet 37 in the lower end of the spring 36,- with the flat head thereof bearing on the flattened top of the rear end of the tension member 16; Therivet fits nicely in the end of the spring, and a reliable bearing is provided thereby for the spring on the tension member;

In my patent above referred tothe ad ust= ing screw 33 is illustrated as having a screw driver slot provided therein for the ad]ustment thereof. It is preferred, however, to

I avoid the necessity for the operator having to use a screw driver to adjust the tension; it is much handier if that can be taken care of with a thumb'nut such as that shown at 38.

Th'e'mere provision of a thumb nut on the adjusting screw, Without making any provision for locking the same in adgusted position, introduces the objections mentioned above; the thurnb'nut and adjusting screw, by rees'onof their having to operate with the vibrator '15, are apt to turn by themselves during the operation of the tool beeause the more friction tending to hold the parts in ad'- j usted position is not suflioien't in the presence of the vibration incident to the operation of the tool, and, furthermore, the fact that the s thumb nut constitutes projeotion on the tool apt to be brushed against something intro duos the likelihood of the tension adjustment being thrown off unbeknownst to the operator during the operation of the tool. To avoid the e difliculties I have provided the thumb nut 38 with a tubular shank 39 preferably formed integral therewith and of approximately the same outside diameter as the trunnion 20. The thumb nut 38 is drilled centrally from the outer end thereof to provide abore 40, the inner end of which is reduced as at 41 slidably t receive stem 42 extending outwaldly from the adjusting screw 33; The reduction in the size of the bore 40 at 41 pro;- vidc's an annular shoulder 43 at the inner end of the tubular shank 39 serving as a seat for one end of coiled compression spring 44 disosed within said tubular shank. The other end of the spring 4 bears against a cross-pin 45 mounted in the outer end of the stem 42, whereby normally to urge the shank-39 of the thumb nut 38 inwardly toward the trunnion 20, for a purpose presently to appear. Now, the thumb nut 38 is slotted longitudinally from the outer end to a point near the inner end of the shank 39 as shown at 46 for reception of the ends of the cross-pin e5 Thus the thumb nut 38 is held against turning relative to the screw 33, although it is free to have endwise movement relative ther to under constraint of the s ring 4 1- A plug 47 threading in the outer end of the bore 40 serves a closure to exclude dirt from the adjustment The inner end of the shank 39 is cas'tellatod as shown at 48 and the end of the trunnion 20 is correspondingly eastelluted as shown at 49, and these portions are arranged to be interlocked when the e'ndfof the shank 39 is urged toward abutment With the end of the trunnion 20 under the action of the spring 44 In operation, it will be seen that when an adj us'tinont of the SCl'GW 33 is to be made the thumb nut 38 is simply pulled out enough to disengage the castellated end 48 of the shank 39 from the c'astellatd end 49 of the trunnion 20, end turned one way or the other depend ing on whether the tension on the cutter l2, hap ens to be too light or too heavy. Then, after the adjustment is made, the thumb nut 38 is simply released and allowed to be interlock d again with the trunnion. In'tliat way the thumb nut 38, screw 33 and trunnion 20 are positively held in a predetermined ad j usted relation to one another, and no amount of operation "of the shear nor any accidental brushing against the thumb nut can possibly aifeet the adjustment. The operator knows definitely that after he has adjusted the tension,the tool will keep that adjustmentuntil he desires to change it. Thus, it will be seen that I'have provided a thumb nut tension adjustment without introducing the. serious objections that have usually gone with that type 5 of adjustment. In order that the nut 38 may not constitute an objectionable projection on the bottom of the tool, I prefer to have the front end of the frame 5 otlset downwardly, as shown at 50, thus bringing the comb 13 into 3 substantially the same plane with the thumb nut 38. The advantage in this is self evident to anyone familiar with the conditions under which a tool of this kind is operated. The plug 23, previously described, is made to lie as close to flush with the top of the frame as possible for similar reasons.

In the operation of the tool, the left hand side of the trunnion if it were allowed to come into direct contact with the inside of the bushing would become worn, due to the fact that when the cutter 12 is placed under tension, the trunnion 20 has sidewise thrust imposed thereon in that direction, the reason for which is undoubtedly evident from examination of Fig. 2. If that were allowed to occur, it will be evident that the shank 39 of the thumb nut 38 would not have the same relationship with the trunnion in any position of ad ustment of the thumb nut; the latter would not be worn the same way on all sides. It is, therefore, important that the trunnion as well as the shank of the thumb nut be kept from wearing at I all and that the wear be taken by some other part. For that reason, I provide a slip-sleeve 51 fitting on the end of the trunnion 20 and arranged to serve as an intermediate wear member and to oscillate with I the trunnion inside the bushing 25. The shank 39 of the thumb nut 38 and the trunnion 20, fit snugly inside the sleeve, and regardless of the amount of wear on the outside of the sleeve incident to its operation in p the bushing 25, it is obvious that the tension adjustment will remain absolutely unaffected and that the thumb nut can be kept in one state of adjustment as long as desired without any danger of the parts becoming worn, so that a change in the adjustment might be difficult to make, because of the parts not being absolutely true with respect to one another on all sides. The inner end of the sleeve 51 is enlarged in diameter, as shown at 52, and

bears on the inner end of the bushing 25.

The trunnion 20 is slightly reduced in diameter at the lower end thereof to fit inside the sleeve 51, in consequence of which an annular shoulder 53 is provided on the trunnion intermediate the ends therefof arranged to bear on the inner end of the sleeve 51. A lug 54- projects from the shoulder 53 and fits in a notch 55 provided in the inner end of the sleeve 51 whereby to lock the sleeve to the trunnion for ostcillation therewith. I prefer to provide two pairs of diametrically opposed notches 55, spaced ninety degrees apart so as to permit the sleeve 51 to be turned with reference to the trunnion and locked thereto in either one of four positions. Any number of notches may, however, be provided, to provide as many possible settings of the sleeve. Thus, when the sleeve 51 has become worn on the left hand side, and it is desired to bring the parts back into their original relationship for smooth and quiet operation of the tool, the plug 23 can be removed or unthreaded just enough to allow the vibrator 15 to be raised sufficiently to permit the sleeve 51 to be turned to bring the next notch 55 thereof into register with the lug 54, whereupon the tool is good for another long period of service before an other similar resetting of the SlCG B should be made.

It is believed the foregoing description conveys a clear understanding of my invention. While I have chosen to illustrate my invention as embodied in one specific form of shear, it should be readily apparent that the invention is not limited to such use. It might be embodied in shears of different constructions. The appended claims have been drawn with that in view and should be accordingly construed.

I claim:

1. In a shearing tool of the character described. the combination with a frame by which the tool is grasped for use, a fixed cutter comb on said frame, a reciprocating cutter cooperating therewith, and an actuator for said reciprocating cutter comprising two members of which the first is fulorumed in said frame for *ibratory action to reciprocate the cutter and the second extends forwardly therefrom for engaging the cutter, the first member supporting the second member whereby the latter is free to have endwise rocking movement to adjust its forward end in relation to the cutter so as to press the same toward the comb, of a screw threaded element mounted in the one member and. engaging the other member positively to adjust the forward end of the second member toward the comb, and a separate part mounted on said element so as to be capable of communicating rotation thereto but arranged to have axial movement relative thereto, said part being also arranged by axial movement to be dctachably interlocked with the actuator so as to be held against turning relative thereto. said part when so interlocked serviug to hold the screw threaded element in adjusted position and when unlocked being arranged to be turned to adjust the screw th rcaded element.

2. In a shearing tool of the character described. the combination with a frame by which the tool is grasped for use, a fixed cutter comb on said frame, a reciprocating cuttor cooperating therewith, and means for ICU ,ing therefrom, and a "actuating said cutter comprising a vibratory member tulcrumcd in said frame and a tension member moving with the vibrator member and tulcrumed on said member for rocking movement relative thereto and extending forwardly therefrom for engagement at its forward end with the cutter, of a screw acting aetween the vibrator member and the tension member to rock the latter relative to the former to force the forward end of the lattel downwardly and press the cutter against the a frame by which the tool is grasped for use,

a tired cutter comb on said frame, a reciproca'lng cutter cooperating therewith, and a vibratory member for reciprocating said cuttor, of a screw mounted in a part oscillating with the vibrator member arranged when adjusted to vary the tension of the cutter on the comb. said screw having a stem extendmanually rotatable thumb nut mounted on said stem so as to be capable of communicating rotation thereto but adapted'to have endwise movement relative thereto to be locked and unlocked, said thumb nut having a portion arranged to be interlocked directly with a part oscillating with the vibrator member.

In a shearing tool, the combination with a frame by which the tool is grasped for use, a fixed cutter comb on said frame, a reciprocating cutter cooperating therewith, and a vibratory member for reciprocating said cutter, of a screw mounted in a part oscillating with the vibrator member arranged when adjusted to vary the tension of the cutter on the comb, said screw having a stem extending therefrom, a manually rotatable thumb nut non-rotatably mounted on said stem so as to be capable of communicating rotation thereto but adapted to have endwise movement relative thereto to be locked and unlocked, said thumb nut having a portion arranged to be interlocked directly with portion of the part in which the screw is mounted, and spring means normally urging the thumb nut in one direction relative to the stem to interlock the thumb nut with said part.

5. In a tension adjustment for a tool of the character described, the combination with a tension member and a part in relation to wiich the same is adjustable, of a screw threading in said part and engaging said of said vibrator member for oscillating the member, said screw having a stem projecting therefrom, a thumb nut mounted on said stem for endwise movement relative thereto, said thumb nut having a slot provided in the wall thereof, a cross pin on the outer end of said stem engaging in said slot serving to hold the thumb nut against turning relative to the stem so as to permit turning the screw by means of the thumb nut, said thumb nut having a portion adapted to be brought into interlocking relation with said part by endwise movement of said thumb nut relative to the stem, and a coiled compression spring mounted in the thumb nut about the stem bearing at its outer end against the cross-pin T and at the inner end against a portion ofsaid thumb nut whereby normally to urge the thumb nut toward interlocked relation with said part,

6. In a shearing tool of the character described, comprising a frame by which the tool is grasped for use, a fixed cutter comb on said frame, a reciprocating cutter cooperating therewith, a vibrator member having upper and lower coaxial trunnion parts received in bearings in said frame to permit oscillatory movement of said member, and a tension member fulcrumed on the vibrator member intermediate its ends and reaching forwardly from the vibrator member for engagement with the cutter to actuate the same and press it against the comb, a screw threading in the lower trunnion part of the vibrator member for engaging the rearward end of M the tension member to urge the same up-' wardly to cause the forwardend thereof to be urged downwardly to press the cutter against the comb, a thumb nut projecting from the bearing for the lower trunnion having a cylindrical shank portion fitting in said bearing below the trunnion, said thumb nut being arranged to be turned by hand and having such connection with said screw whereby to turn the latter therewith but permit movement of the nut endwise relative thereto, and means for detachably locking the thumb not for oscillation with the lower trunnion whereby to hold the screw in adjusted position, the nut being arranged to be locked and unlocked v by endwise movement thereof. .7. In a shearing tool of the character described comprising a frame by which the tool -1s grasped for use,a fixed cutter comb on said frame, a reciprocating cutter cooperat- 111g therewith, a vlbrator member having upper and lower coaxial trunnion parts arranged to be received in bearings in said frame to permit oscillatory movement of said member, means connected with the one arm same, means on the other end of said vibrator member having connection with the cutter for reciprocating the same under tension on the comb, a bearing for the upper trunnion part "of the vibrator member, said bearing being in whereby any wear at this point incident to the operation of the vibrator is assumed by the sleeve instead of the trunnion, said sleeve being arranged to he turned with reference to the trunnion and secured thereto in different positions of adjustment so that when one portion thereof is worn excessively the sleeve can be turned to bring an unworn portion thereof into position for use.

8. In a shearing tool of the character described, comprising a frame having a part for holding the tool, a fixed cutter comb on said frame, a reciprocating cutter cooperating therewith, a vibrator member fulcrumed in the frame for vibratory action, the same having a trunnion on the fulcrum axis arranged to he received in a bearin g on the frame, a tension member on the vibrator member having the end thereof to be adjusted intersecting the fulcrum axis of the vibrator member, a screw threaded part in the aforesaid trunnion having connection with the tension member whereby to operate the same to place the cutter under the desired tension, a bearing sleeve fitting the outside of the trunnion and arranged to oscillate therewith in a bearing on said frame, another part fitting in the sleeve and projecting from the frame for manual operation, said part being fixed to the aforesaid screw threaded part whereby when the same is turned the screw threaded part is adjusted, and means for detachably securing the last mentioned part to the trunnion within said sleeve.

9. In a shearing tool of the character described, comprising a frame having a part for holding the tool, a fixed cutter comb on said frame, a reciprocating cutter cooperating therewith, a vibrator member fulcrumed in said frame for vibratory action, the same having a lower trunnion part on the fulcrum axis arranged to be received in a bearing in said frame, an adjusting screw threading in said trunnion. a tension member mounted on the vibrator member and having the screw bearing against one end thereof to place the cutter under tension according to the adjustment of said screw, a bearing sleeve having said trunnion fitting in the upper end thereof, a bearing on said f ame receiving substantially the full length of said sleeve, an adjusting thumb nut having a hollow cylindrical shank fitting in the lower end of said sleeve under the end of the trunnion, said nut being connected with said screw so as to permit the screw to be turned thereby while permitting endwise movement of the hollow cylindrical shank thereof relative to the screw, spring means normally urging the shank inwardly toward the trunnion and means on the abutting ends of the shank and trunnion for securing the two parts together.

10. In a shearing tool of the character described comprising a frame having a fixed cutter comb thereon, a cutter adapted to be reciprocated relative to the comb and held against the comb under tension, and a forked member arranged to be detachably connected with the cutter for reciprocating the same, said cutter having a pair of laterally spaced holes and said forked member having projecting points for reception in said holes for conmeeting the said parts, the points being rounded on the ends thereof and the holes being correspondingly counter-bored for reception thereof whereby the points are arranged to be self-seating and self-adjusting in said holes, and said points being further provided with nibs on the ends thereof ar 'anged to project freely through said holes whereby not only to permit a slight amount of movement of the points in said holes but also positively hold the cutter on the points when the points are held in the holes under light tension.

11. A tool as set forth in claim 8, wherein the sleeve is arranged to be turned with reference to the trunnion and secured thereto in different positions f adjustment so that when one portion thereof worn excessively the sleeve can be turned to bring an unworn portion thereof into position for use.

In witness of the foregoing I afiix my sig nature.

FRANK W. SCOTT.

CERTIFICATE OF CORRECTION.

Patent No. 1,825,890. Granted October 6, 1931, to

FRANK W. SCOTT.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 5, line 50, claim 4, strike out "non-rotatably; lines 55 to 57, same claim, strike out the words "portion of the part in which the screw is mounted" and insert part oscillating with the vibrator member; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 9th day of February, A. D. 1932.

M. J. Moore, (Seal) Acting Commissioner of Patents. 

